package easy;

import java.util.HashMap;
import java.util.Map;

/**
 * Created by daodao on 2017/12/1.
 * Problem 27
 * Description: Given an array and a value, remove all instances of that value in-place and return the new length.
 * Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1)
 * extra memory. The order of elements can be changed. It doesn't matter what you leave beyond the new length.
 *
 * Example: Given nums = [3,2,2,3], val = 3,
 * Your function should return length = 2, with the first two elements of nums being 2.
 */
public class RemoveElement {
    public static int removeElement(int[] nums, int val) {
        int newLen = nums.length;
        Map<Integer, Integer> map = new HashMap<>();
        for (int i = 0, j = 0; i < nums.length; i++) {
            if (nums[i] != val) {
                map.put(j, nums[i]);
                j++;
            } else {
                newLen--;
            }
        }
        for (int j = 0; j < newLen; j++) {
            nums[j] = map.get(j);
        }
        return newLen;
    }
}
